xref: /openbmc/linux/arch/mips/sgi-ip32/ip32-reset.c (revision 63dc02bd)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2001 Keith M Wesolowski
7  * Copyright (C) 2001 Paul Mundt
8  * Copyright (C) 2003 Guido Guenther <agx@sigxcpu.org>
9  */
10 
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/notifier.h>
15 #include <linux/delay.h>
16 #include <linux/ds17287rtc.h>
17 #include <linux/interrupt.h>
18 #include <linux/pm.h>
19 
20 #include <asm/addrspace.h>
21 #include <asm/irq.h>
22 #include <asm/reboot.h>
23 #include <asm/wbflush.h>
24 #include <asm/ip32/mace.h>
25 #include <asm/ip32/crime.h>
26 #include <asm/ip32/ip32_ints.h>
27 
28 #define POWERDOWN_TIMEOUT	120
29 /*
30  * Blink frequency during reboot grace period and when panicked.
31  */
32 #define POWERDOWN_FREQ		(HZ / 4)
33 #define PANIC_FREQ		(HZ / 8)
34 
35 static struct timer_list power_timer, blink_timer, debounce_timer;
36 static int has_panicked, shuting_down;
37 
38 static void ip32_machine_restart(char *command) __attribute__((noreturn));
39 static void ip32_machine_halt(void) __attribute__((noreturn));
40 static void ip32_machine_power_off(void) __attribute__((noreturn));
41 
42 static void ip32_machine_restart(char *cmd)
43 {
44 	crime->control = CRIME_CONTROL_HARD_RESET;
45 	while (1);
46 }
47 
48 static inline void ip32_machine_halt(void)
49 {
50 	ip32_machine_power_off();
51 }
52 
53 static void ip32_machine_power_off(void)
54 {
55 	unsigned char reg_a, xctrl_a, xctrl_b;
56 
57 	disable_irq(MACEISA_RTC_IRQ);
58 	reg_a = CMOS_READ(RTC_REG_A);
59 
60 	/* setup for kickstart & wake-up (DS12287 Ref. Man. p. 19) */
61 	reg_a &= ~DS_REGA_DV2;
62 	reg_a |= DS_REGA_DV1;
63 
64 	CMOS_WRITE(reg_a | DS_REGA_DV0, RTC_REG_A);
65 	wbflush();
66 	xctrl_b = CMOS_READ(DS_B1_XCTRL4B)
67 		   | DS_XCTRL4B_ABE | DS_XCTRL4B_KFE;
68 	CMOS_WRITE(xctrl_b, DS_B1_XCTRL4B);
69 	xctrl_a = CMOS_READ(DS_B1_XCTRL4A) & ~DS_XCTRL4A_IFS;
70 	CMOS_WRITE(xctrl_a, DS_B1_XCTRL4A);
71 	wbflush();
72 	/* adios amigos... */
73 	CMOS_WRITE(xctrl_a | DS_XCTRL4A_PAB, DS_B1_XCTRL4A);
74 	CMOS_WRITE(reg_a, RTC_REG_A);
75 	wbflush();
76 	while (1);
77 }
78 
79 static void power_timeout(unsigned long data)
80 {
81 	ip32_machine_power_off();
82 }
83 
84 static void blink_timeout(unsigned long data)
85 {
86 	unsigned long led = mace->perif.ctrl.misc ^ MACEISA_LED_RED;
87 	mace->perif.ctrl.misc = led;
88 	mod_timer(&blink_timer, jiffies + data);
89 }
90 
91 static void debounce(unsigned long data)
92 {
93 	unsigned char reg_a, reg_c, xctrl_a;
94 
95 	reg_c = CMOS_READ(RTC_INTR_FLAGS);
96 	reg_a = CMOS_READ(RTC_REG_A);
97 	CMOS_WRITE(reg_a | DS_REGA_DV0, RTC_REG_A);
98 	wbflush();
99 	xctrl_a = CMOS_READ(DS_B1_XCTRL4A);
100 	if ((xctrl_a & DS_XCTRL4A_IFS) || (reg_c & RTC_IRQF )) {
101 		/* Interrupt still being sent. */
102 		debounce_timer.expires = jiffies + 50;
103 		add_timer(&debounce_timer);
104 
105 		/* clear interrupt source */
106 		CMOS_WRITE(xctrl_a & ~DS_XCTRL4A_IFS, DS_B1_XCTRL4A);
107 		CMOS_WRITE(reg_a & ~DS_REGA_DV0, RTC_REG_A);
108 		return;
109 	}
110 	CMOS_WRITE(reg_a & ~DS_REGA_DV0, RTC_REG_A);
111 
112 	if (has_panicked)
113 		ip32_machine_restart(NULL);
114 
115 	enable_irq(MACEISA_RTC_IRQ);
116 }
117 
118 static inline void ip32_power_button(void)
119 {
120 	if (has_panicked)
121 		return;
122 
123 	if (shuting_down || kill_cad_pid(SIGINT, 1)) {
124 		/* No init process or button pressed twice.  */
125 		ip32_machine_power_off();
126 	}
127 
128 	shuting_down = 1;
129 	blink_timer.data = POWERDOWN_FREQ;
130 	blink_timeout(POWERDOWN_FREQ);
131 
132 	init_timer(&power_timer);
133 	power_timer.function = power_timeout;
134 	power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
135 	add_timer(&power_timer);
136 }
137 
138 static irqreturn_t ip32_rtc_int(int irq, void *dev_id)
139 {
140 	unsigned char reg_c;
141 
142 	reg_c = CMOS_READ(RTC_INTR_FLAGS);
143 	if (!(reg_c & RTC_IRQF)) {
144 		printk(KERN_WARNING
145 			"%s: RTC IRQ without RTC_IRQF\n", __func__);
146 	}
147 	/* Wait until interrupt goes away */
148 	disable_irq_nosync(MACEISA_RTC_IRQ);
149 	init_timer(&debounce_timer);
150 	debounce_timer.function = debounce;
151 	debounce_timer.expires = jiffies + 50;
152 	add_timer(&debounce_timer);
153 
154 	printk(KERN_DEBUG "Power button pressed\n");
155 	ip32_power_button();
156 	return IRQ_HANDLED;
157 }
158 
159 static int panic_event(struct notifier_block *this, unsigned long event,
160 		       void *ptr)
161 {
162 	unsigned long led;
163 
164 	if (has_panicked)
165 		return NOTIFY_DONE;
166 	has_panicked = 1;
167 
168 	/* turn off the green LED */
169 	led = mace->perif.ctrl.misc | MACEISA_LED_GREEN;
170 	mace->perif.ctrl.misc = led;
171 
172 	blink_timer.data = PANIC_FREQ;
173 	blink_timeout(PANIC_FREQ);
174 
175 	return NOTIFY_DONE;
176 }
177 
178 static struct notifier_block panic_block = {
179 	.notifier_call = panic_event,
180 };
181 
182 static __init int ip32_reboot_setup(void)
183 {
184 	/* turn on the green led only */
185 	unsigned long led = mace->perif.ctrl.misc;
186 	led |= MACEISA_LED_RED;
187 	led &= ~MACEISA_LED_GREEN;
188 	mace->perif.ctrl.misc = led;
189 
190 	_machine_restart = ip32_machine_restart;
191 	_machine_halt = ip32_machine_halt;
192 	pm_power_off = ip32_machine_power_off;
193 
194 	init_timer(&blink_timer);
195 	blink_timer.function = blink_timeout;
196 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
197 
198 	if (request_irq(MACEISA_RTC_IRQ, ip32_rtc_int, 0, "rtc", NULL))
199 		panic("Can't allocate MACEISA RTC IRQ");
200 
201 	return 0;
202 }
203 
204 subsys_initcall(ip32_reboot_setup);
205